A lost motion connection is a known mechanism technique for permitting selective movement of members.
In the environment of the present invention, the selective lost motion is used to alternately permit an engine throttle valve to be controlled directly by the operator or through an automated speed control system. More specifically, the speed control system can function in an "on" mode or an "off" mode and be selectively coupled or decoupled, respectively, to the throttle valve. In the "on" mode, a direct connection of the speed control linkage is desired. Alternately, in the "off" mode, the throttle valve position is controlled through a direct connection of the accelerator pedal linakage, and movement of the device controlling the throttle valve position (e.g. a bell crank) should not effect corresponding movement of the speed control linkage. Thus, a lost motion connection of the speed control linkage with the throttle valve control member is desired when the vehicle is operated with the speed control system in the "off" mode.
Moreover, a lost motion control linkage for a speed control system is subject to the throttle closing time parameters imposed by Federal Motor Vehicle Safety Standard 124. This regulation required throttle closing to take place within a prescribed time limit through a full range of operating temperatures.
Additionally, the design of the lost motion connection should admit to easy and secure assembly with automobile engines on a mass production basis.
One previously known form of lost motion link for a throttle valve comprises an elongated link having an elongated slot therein. The link is secured at one end of the cable and the elongated slot is sized to loosely recieve a pin extending outwardly from the throttle actuator. The link is entrained on the pin by means of a washer and a locking clip extending through an aperture in the actuator pin. Thus, a plurality of parts must be manufactured and assembled in order to construct the previously known lost motion links used for throttle valves. Moreover, the link is exposed to environmental conditions and can corrode or become clogged and thus depart from the desired operating characteristics.
Another known type of lost motion link comprises a housing defining an elongated chamber adapted to receive an enlarged endbead on one end of a cable. The housing includes an apertured flange adapted to be received on an actuator pin and the flange is entrained on the pin by a washer and a locking pin in the previously known manner. The housing also includes a removable cap section so that the beaded end of the cable can be received in the housing by drawing the cable through the housing so that it protrudes from one end of the housing. The single open end of the housing exposes the bead, chamber and cable to an accumulation of contaminants and corrosive materials such as salt which can enter the engine compartment and thus effect operation of the lost motion linkage. This problem can be especially bothersome when the cable is aligned at an upward angle with respect to the throttle pin.